Once it sailed inside the foul pole and landed in the lower left field seats, he had salvaged a victory for the Los Angeles Dodgers after their bullpen almost gave it away.
Kemp hit a go-ahead home run leading off the eighth inning, lifting the Dodgers to a 3-2 win over the St. Louis Cardinals on Saturday night and evening their NL Division Series at a game apiece.
"This was big for us," he said. "I feel like we definitely do have the momentum. We got continue to go, though."
The crowd of 54,599 erupted in cheers as Kemp rounded the bases. Bubbles percolated into the hot night air from a machine in the dugout the Dodgers turn on to celebrate homers.
"It seemed like a mistake pitch to Matt and he's been hot, as everyone knows, and that was exciting," Dodgers starter Zack Greinke said.
No one looked happier greeting Kemp in the dugout than a once-distraught J.P. Howell, who had served up a tying, two-run homer to Matt Carpenter in the top of the inning after relieving Greinke. Kemp hugged Howell, who pointed skyward in relief.
"It was incredible, man," Howell said. "To me it was almost religious because I was praying so hard and it happened pretty quickly. I was pretty thankful."
Kemp connected against Pat Neshek for his fifth hit in the best-of-five series.
"He tried to get me with a couple of sliders," Kemp said. "I laid off some tough ones that were close on the plate, but he left one just out on the plate that I could do something with and I put a good swing on it."
Game 3 is Monday night in St. Louis, with John Lackey starting for the Cardinals against Hyun-Jin Ryu of the Dodgers.
"It was there for us and we let it slip away," Cardinals manager Mike Matheny said.
Brandon League got his first career post-season win with a scoreless inning of relief. Kenley Jansen retired the side, striking out two, in the ninth to earn the save.
"Now we just got to get our rest in and try to beat the Cardinals at their place, just like they did here in the first game," Jansen said. "Got to go there and steal one."
Greinke pitched two-hit ball over seven scoreless innings a night after ace Clayton Kershaw gave up Carpenter's go-ahead three-run double in the seventh that helped the Cardinals win 10-9.
The low-key Greinke, who has pitched in Kershaw's shadow the last few years, tried not to put any extra pressure on himself to deliver a win.
"Any time personally I try to do more than I feel I'm capable of, it backfires," he said. "My game plan is always to try to lower my expectations and not try to do too much."
Greinke belatedly took the mound in the eighth after his teammates had already taken their positions. Manager Don Mattingly came out to get him, and Greinke left to a standing ovation.
"We're seeing two teams that don't really want to go home and that are fighting for every game and every out and every pitch," Mattingly said. "It's what everybody wants to see at this time of year."
Howell took over and promptly gave up a single to pinch-hitter Oscar Tavares before Carpenter tied it at 2. Carpenter is 4 for 8 in the series, with two homers, two doubles and six RBIs.
"I'm just trying to be aggressive," Carpenter said. "I'm getting some good pitches to hit, putting some good swings on it. I don't think there's any rhyme or reason to it."
Greinke struck out seven, walked two and didn't allow a runner past second base. He didn't give up a hit until the fifth, when Kolten Wong doubled down the right-field line before Greinke struck out the next two batters to end the inning.
Greinke was pretty nifty at the plate, too. He went 2 for 3 for his first career post-season multihit game, and even slid headfirst into third on Dee Gordon's single in the fifth that eluded Wong's dive at second base.
"It's really important fielding your position and hitting, not being an absolute out," Greinke said.
Cardinals starter Lance Lynn gave up two runs and seven hits in six innings, struck out eight and walked two.
The Dodgers took a 2-0 lead in the third. Gordon's groundout to second base scored A.J. Ellis, who doubled leading off for his fifth hit of the series. Adrian Gonzalez's two-out RBI single made it 2-0, with Greinke scoring from second.
Mattingly had earlier challenged a call that Greinke was tagged out going to second. After a review, the umpires ruled him safe when Wong tagged Greinke with his empty glove after Wong had already moved the ball to his throwing hand to try for a double play.
The teams that share a combustible history in the playoffs were under control, even after Greinke hit Cardinals centre fielder Jon Jay with a pitch in the first inning. Unlike a night earlier, when Yasiel Puig's plunking by Adam Wainwright triggered a benches-clearing scrum, everyone stayed put in their dugouts.
Puig, who drew attention with his neon-green batting gloves, struck out on a high fastball from Lynn in his first at-bat. Catcher Yadier Molina appeared to say something to Puig, who reacted and had to be walked part way back to the dugout by umpire Rob Drake. Puig struck out four times.
Molina and Gonzalez yelled in each other's faces in Game 1 as both benches and bullpens emptied without punches being thrown.
Matheny didn't consider the talk about his hitters allegedly stealing signs in Game 1 to be a compliment.
"That would be an insult. Absolutely," he said. "Our guys go about their at-bats like pros. It's just rumour and right now it could just be a distraction."
The suggestion that Kershaw might have been tipping his pitches on Friday generated a lot of talk among the game's TV announcers and on Twitter.
"I'll be the first one to say that there's nothing to it," Cardinals centre fielder Jon Jay said.
Mattingly said he knows most teams try to give their hitters the location of pitches, but he knows of only one player who ever relayed pitch signs from second base to the hitters. He declined to name the player except to say he's still active.
"We know they're trying to do it and everybody tries to do it," he said. "We're switching signs, you do all this stuff. It's just not that easy, so it's execution."
Cardinals: Lackey (3-3, 4.30 ERA) needs 3 2-3 innings to become the active leader in post-season innings pitched and overtake leader CC Sabathia with 107 1-3. The right-hander hasn't lost a division series game since Oct. 1, 2008, against Boston when he was with the Los Angeles Angels.
Dodgers: Ryu (14-7, 3.38) hasn't pitched since Sept. 12 while rehabbing from left shoulder irritation, but Mattingly isn't worried. "He seems to be able to not throw a whole lot and be pretty sharp," the manager said.